1. Field of the Invention
This invention relates to methods for manufacturing magnetic sensors for measuring bearings (or azimuths). This invention also relates to lead frames for use in magnetic sensors.
2. Description of the Related Art
In general, magnetic sensors are used to detect magnetism for the purpose of measurement of bearings with regard to external magnetic fields applied thereto.
FIG. 83 shows a conventionally-known magnetic sensor unit 64 in which magnetic sensors 51 and 61 are arranged on a surface 63a of a board (or substrate) 63. This magnetic sensor unit 64 is capable of measuring bearings of an external magnetic field in a three-dimensional manner.
Specifically, the magnetic sensor 51 includes a magnetic sensor chip 52 sensitive to components of an external magnetic field in two directions, wherein there are provided two sensing directions (namely, an X-axis direction and a Y-axis direction), which are orthogonal to each other on the surface 63a of the board 63. The magnetic sensor 61 includes a magnetic sensor chip 62 sensitive to components of an external magnetic field in a single direction only, wherein a sensing direction lies in a vertical direction (namely, a Z-axis direction) orthogonal to the surface 63a of the board 63.
Bearings of an external magnetic field are determined as vectors in a three-dimensional space upon detection of three-directional components of magnetism measured by the magnetic sensor chips 52 and 62.
As described above, the conventionally-known magnetic sensor unit 64 provides the magnetic sensor chips 52 and 62 for the magnetic sensors 51 and 61 respectively. Therefore, in the manufacture of the magnetic sensor unit 64, it is necessary to produce the magnetic sensors 51 and 61 respectively and to arrange them on the surface 63a of the board 63 at respective positions. This increases the number of steps in the manufacture of the magnetic sensor unit, thus increasing the manufacturing cost therefor.
In addition, the conventional magnetic sensor unit 64 has difficulties in accurately arranging the magnetic sensor 61 in the surface 63a of the board 63 so that the sensing direction of the magnetic sensor chip 62 becomes orthogonal to the sensing direction of the magnetic sensor chip 52.